This is a relatively large dorid with a wide mantle skirt, growing to at least 8 cm in length. The mantle is covered is microscopic spiculate tubercules which makes the mantle surface quite rough to the touch. It varies from brown to a pinkish or whitish colour with scattered large brownish spots and smaller whitish ones. The translucent whitish gills are large and branched and the rhinophores are also pale in colour.

The clown nudibranch is easily spotted in the Poor Knights Islands where it feeds on bryozoans. It also shows considerable colour variation through out its range. In Western Australia the orange spots are very small. Moving east, the orange spots become larger being.

The clown nudibranch is easily spotted in the Poor Knights Islands where it feeds on bryozoans. It also shows considerable colour variation through out its range. In Western Australia the orange spots are very small. Moving east, the orange spots become larger being very large In New Zealand.